IP addressing Flashcards
What is a IP address
An unique numerical address that identifies a host device or a device attempting to communicate over IP on a network
Difference between IPv4 and IPv6
IPv6 gives more possible addresses compared to IPv4
What is the network identifier
The left hand bits of 32-bit number
Defines the network where nodes are communicating
What is the host identifier
Right hand bits of 32-bit number
Identifies separate nodes on a network
What are the reserved addresses
x.y.z.0 is the network IP address
x.y.z.255 is the broadcast address
127.x.y.z is reserved for loopback
What does subnetting do
Breaking the number available for the hostIDs between individual subnetworks
Why is subnetting useful
Reduces broadcast domain, improves security
Reduce data collision
What is the subnet mask
Used with the IP address to identify the network (and subnet) in the address
It will have the first n bits set to 1 and the rest to 0
How does a subnet mask work
When you AND a IP address and the subnet mask the network ID is found but the host ID is hidden
What is Class Inter-Domain routing
CIDR
Used to replace classful addressing. Allows user to use variable length subnet masks (VSLM)
What does a CIDR need
It has to be contiguous
Why is CIDR used
Create VLSMs which uses less wastage of IP addresses.
What is DHCP
Dynamic Host Configuration Protocol
Used to automatically assign IP addresses and other network configuration
What does DHCP allow
Limited pool of IP addresses to be shared
Allow hosts to reconfigure themselves when moving between networks
Reduces number of IP addresses needed locally
What is a port
A virtual place within the OS where network connections start and end. Help computers sort traffic
What does a socket contain
3 parts
protocol, local IP address, local port
What is Network Address Translation
A NAT
As devices on private IP address cannot access the internet a NAT is required
How does a NAT work
Allows a single public IP address to be shared by any number of hosts with private IP addresses
The translation device holds the source and destination for each request
It then communicates on host behalf to destination IP
When it receives a response it sends the message back to the host
What is Port forwarding
A networking technique that allow private network access the internet.
It will be given a non-routable IP address in a private network
Public request reaches external router of private network using given port
Data packets are then forwarded internally to the correct device
